The present invention relates to a process for the hydrocracking of heavy oils. More particularly, it relates to a process for efficiently hydrocracking heavy oils in the presence of a catalyst comprising a carrier and active components deposited on the carrier, said carrier being composed of aluminosilicate subjected to a specific treatment and inorganic oxide, to convert the heavy oils into lighter oils of higher value.
In recent years, there has been a strong upward tendency in production of heavy crude oils all over the world, and further, the demand for petroleum has changed. Thus, presently, lighter oils tend to be in short supply, although heavy oils are supplied in surplus. For this reason, a number of techniques have been developed for the conversion of heavy oils into lighter oils such as naphtha, kerosene, and light oil. Of these techniques, hydrocracking has received increasing attention because it provides lighter oils of good quality.
Conventional hydrocracking methods, however, have various disadvantages--e.g., the yield of an intermediate fraction (corresponding to kerosene and light oil) is low, and the amount of hydrogen being consumed is large.
A catalyst, therefore, has recently been developed in which a specific crystalline aluminosilicate treated with an aqueous solution of iron salt is used as a carrier (see Japanese Patent Application No. 100546/1981). When this catalyst is used in hydrocracking of heavy oils, it can maintain its high activity over long periods of time, because the heat resistance of the catalyst is high and the amount of carbon deposited is small. This catalyst, however, suffers from disadvantages in that the yield of an intermediate fraction is still low and the amount of hydrogen being consumed cannot be greatly reduced to the extent that is satisfactory, although it is slightly reduced compared with the conventional methods.